Electromagnetic relay with readily demountable parts



y 1966 1.. E. LAWRENCE ETAL 3,251,964

ELECTROMAGNETIC RELAY WITH READILY DEMOUNTABLE PARTS Filed Dec. 26, 1965 6 Sheets-Sheet 1 11- g M "Nu p INVENTORS LELAND E. LAWRE NCE JOHN L. HAYDU Mammy/MK AT TOR NEY May 17, 1966 L. E. LAWRENCE ETAL ELECTROMAGNETIC RELAY WITH READILY DEMOUNTABLE PARTS 6 Sheets-Sheet 2 Filed Dec. 26, 1963 E C N E R 0 N L A N W D L LIV ATTORNEY May 17, 1966 L. E. LAWRENCE ETAL ELECTROMAGNETIC RELAY WITH READILY DEMOUNTABLE PARTS Filed Dec. 26, 1965 6 Sheets-Sheet 5 Magi L l 63'.v

wig?

5/ INVENTORS LELAND E. LAWRENCE JOHN L. HAYDU AT TORNEY y 1956 L. E. LAWRENCE ETAL 3, 51,964

ELECTROMAGNETIC RELAY WITH READILY DEMOUNTABLE PARTS Filed Dec. 26, 1963 6 Sheets-Sheet 4 INVENTORS LELAND E. LAWRENCE JOHN L. H AYDU ATTORNEY May 17, 1966 L. E. LAWRENCE ETAL ELECTROMAGNETIC RELAY WITH READILY DEMOUNTABLE PARTS Filed Dec. 26, 1963 6 Sheets-Sheet 5 INVENTORS LELAND E.LAWRENCE JOHN L. HAYDU ATTORNEY y 1966 L. E. LAWRENCE ETAL 3,251,964

ELECTROMAGNETIC RELAY WITH READILY DEMOUNTABLE PARTS Filed Dec. 26, 1963 6 Sheets-Sheet 6 INVENTORS LELAND E. LAWRENCE JOHN L. H AYDU AT TORNEY United States Patent Ofiice 3,251,964 Patented May 17, 1966 This invention relates to electrical relays and operating magnets there-for.

Relays for machine tool control and similar applications must operate reliably over an extended life, and it is a purpose of the present invention to provide such a device. In many applications the control circuits are extremely complex and large numbers of control contacts are re quired, which are subject to repeated switching. Large banks of relays are consequently quite common in many electrical controls, and the relays employed must not only be reliable, so as to minimize downtime for correcting faults in the controls of a machine or device, but should also be compact to facilitate mounting large numbers of relays in a minimal space.

It is desirable that control relays fulfill a number of additional criteria, and to provide a relay having multiple features that will make it particularly advantageous, the following objects and advantages are made available in th relay of the invention.

First, it is an object of this invent-ion to have -a magnet assembly that is compact and which can be disassembled by a few simple manual movements whereby repair can be readily effected. In this disassembly a coil block, magnetic yoke and magnetic armature can be removed as a unit from a base frame by simply depressing the block and sliding it out from the frame in a transl-atory movement.

Individual contact assemblies which are mounted upon the base frame, to have a complete relay, are undisturbed and are left intact, and hence the magnet assembly and the contacts are separate components that can be replaced or otherwise altered independent of one another.

A further object is to provide a magnet assembly of a minimum number of parts which interfit in such manner that they can only be assembled in correct orientation with one another. The magnet yoke and armature only fit the coil block in one preselected position, and the coil block slides into a channel shaped base from one end and in one direction of translation. The coil block is preferably of molded material to achieve the intricate configuration desirable for proper fitting of the parts, and upon being slid into the channel shaped base it is caught by a simple catch, and held tightly by associated springs. No screws or other separate parts are required for this assembly. The contact structure, in turn, sits upon the channel shaped base, and does not obstruct movement of the coil block and magnetic members as they are translated into and from the base.

A further object of the invention is to have a relay comprised of an electromagnet and a multiple contact structure of long, trouble-free life to enhance reliability of the device.

It is another object of the invention to have contacts that are readily converted from normally closed to normally open position. This conversion can be made for individual poles, that is a set of stationary and movable contacts, without disturbing other poles, and to make theconversion an extremely simple matter each pole is an enclosed unit that need only be inverted to convert from one contact condition to the other. Such structure enhances the feature of rapid adaptation of the relay to a particular circuit requirement, and accordingly provides improved relay systems.

A particular feature is the use of bias springs to move contacts into their operated positions, rather than a driving force of the magnet armature. The armature is spring biased to its open position, and in this position the armature holds the contacts in their normal positions against opposing contact actuating springs. Thus, upon magnet energization the armature is retracted and springs actuate the contacts to their operated positions. Gravity and armature closing forces are thereby eliminated as actuating forces, and the relay can be mounted at any angle of repose.

A further object is to provide a relay in which the number of necessary contacts can be incorporated without requiring any modification of design or assembly, thereby making the relay highly versatile to satisfy numerous switching applications.

The foregoing and other objects and advantages ofthis invention will appear from the description to follow. In the description reference is made to the accompanying drawings which form a part hereof and in which there is shown by way of illustration :3. specific embodiment for the invention. This embodiment will be described in sufficient detail to enable those skilled in the art to practice this invention. The invention may also reside in other embodiments and various modifications and rearrangements, as may occur to one practicing the art. Consequently, the following detailed description is not to be taken in a limiting sense; instead the scope of the invention is best defined by the claims at the end of this specification.

Referring now to the drawings:

FIG. 1 is a side view in elevation of a relay embodying the invention,

FIG. 2 is a side view in elevation of the magnet assembly of the relay shown in FIG. 1, with a side wall of the base frame thereof broken away to better illustrate the interior,.

FIG. 3 is a plan view of the magnet assembly shown in FIG. 2 with parts broken away and in section,

FIG. 4 is a front end view in elevation of the magnet assembly with parts broken away and in section,

FIG. 5 is a view in perspective of a base frame forming a part of the magnet assembly,

FIG. 6 is a view in perspective of a coil block forming a part of the magnet assembly together with springs that seat in the block,

FIG. 7 is a view in perspective of a magnetic yoke forming a part of the magnet assembly,

FIG. 8 is a view in perspective of a magnetic armature forming. a part of the magnet assembly,

FIG. 9 is a composite view taken from one end of the relay which comprises the base frame of FIG. 5 to which is mounted a lower contact housing and which has an upper contact housing and a cover raised above their normal assembled positions, in order to facilitate an illus tration thereof,

FIG. 10 is a plan view of the entire relay shown in FIG. 1, I

FIG. 11 is a view in cross section of the parts shown in FIG. 9 when assembled, and viewed through the plane 11*11 shown in FIG. 10,

12 is a view in cross section, on an enlarged scale, of the interior of the contact housings as viewed through the plane 12-12 in FIG. 11, this view depicting movabl contacts in a normally closed position,

FIG. 13 is a view in cross section, on an enlarged scale, of the interior of the contact housings as viewed through the plane 13-.13 shown in FIG. 11, in which view contacts are shown in a normally open position,

FIG. 14 is a view in cross section, on an enlarged scale, of the interior of the contact housings as viewed through the plane 14 14 shownin FIG. 11, in which view manually engageable armature actuating plungers are shown,

FLIG. 15 is a view in perspective of a vertically movable button that functions as a spring seat and contact actuator in both the upper housing and the cover of the relay,

FIG. 16 is a view in perspective of a cover forming a part of the relay and which can be fastened atop either the lower or upper contact housing,

FIG. 17 is a view in perspective of the lower contact housing with a manual plunger and a pair of contact assemblies mounted therein,

FIG. 18 is a view in perspective of the upper contact housing with a manual plunger and one contact assembly mounted therein, V

FIG. 19 is a view in perspective of the manual plunger used in the upper contact housing,

FIG. 20 is a view in perspective of a contact assembly as used in the lower contact housing, and

FIG. 21 is a view in perspective of a contact assembly as used in the upper contact housing.

The general arrangement of the relay shown in the drawings is depicted in FIG. 1, where a magnet assembly 1 supports a lower contact housing 2 and an upper contact housing 3 to which is ailixed a small cover 4. The contact housings 2 and 3 mount contact sub-assemblies which expose readily accessible terminals, so that the relay may be conveniently wired into a circuit. The magnet assembly 1 includes an operating coil and magnetic components comprising a yoke and armature, such that when the coil is deenergized the armature holds the contacts in what may be termed their normal positions. Such normal positions for the contacts may be either normally closed or normally open, and the term normal pertains primarily to that condition of a contact when the relay is unenergized. Upon energization of the operating coil the armature will be moved so that operating springs for the individual movable contacts can urge the contacts into their operated position. Such an operation is quite normal for relay structures, and the positive retention of the contacts in either the normal or operated positions, by either the force of the armature or that of an actuating spring, is desirable, so that gravity forces are not relied upon in the operation of the device. The relay may then be mounted in any of several positions, and while the relay in the drawing is indicated in an upright, or vertical position it may be quite normal to mount the relay in the horizontal. An example of such a mounting would be upon a vertical control panel, and in such an application the contact housings 2, 3 might be referred to as front and rear housings, however, for the expedient of describing the relay in the drawings the terms upper and lower have been utilized to agree with the particular orientation shown.

In describing the relay its component sub-assemblies will be covered by appropriate sub-headings herein.

The magnet assembly a coil block 6 (FIG. 6), a magnetic yoke 7 (FIG. 7),

and a magnetic armature 8 (FIG. 8). Referring now to FIG. 5, itsis seen therein that the base frame is of a channel-like configuration, with a floor 9, and parallel side walls :10 extending upwardly from opposite edges of the floor 9. The upper margins of the side walls it) are "shaped to provide an upstanding ear .11 on each wall, inwardly turned ledges =12 that overhang the floor 9 at the rear of the frame -5, a pair of inwardly turned ledges 13 directly to the front of the upstanding cars 11, and a third pair of inwardly turned ledges 14 at the front of the base frame 5. The front ledges 14 are at a slightly higher elevation than the ledges '12 and 13, and the rear ledges '12 and front ledges 14 include appropriate threaded mounting holes 15 for securing the lower contact housing 2 in place. The rear ledges 12 also include arresting notches 16 which engage the coil block 6 and limit the movement of the coil block 6 as it is moved with a slid- 7 ing motion into the channel like base :frame 5.

Alongside the lower, inside margins of the side walls 10 there is a pair of curved springs 17 riveted at one end to the floor 9, such springs being depressible in a vertical direction upon insertion of the coil block 6 in the frame 5. Medially disposed in the floor 9 is a resilient shock absorbing construction consisting of a thin sheet metal plate !18, which has ears at opposite ends engaged in openings in the door 9, as seen in FIG. '2, and interposed between the plate 18 and the door *9 is a resilient cushion 19. This shock absorbing construction functions to engage the lower face of the magnetic yoke 7, so as to absorb shock impacts delivered to the yoke in operation of the magnet;

The coil block 6 (particular reference is made to FIG. 6) is of a molded resin and has an intricate configuration that allows the block to have several functions. These functions are, primarilyflto interfit with the base frame 5 in a tightly held engagement without assembly screws or the like, to present support and guiding for the movable armature 8, to provide a receptacle for the magnetic yoke 7 to accurately pos-itionthe yoke 7 and retain it in place, to house coil windings which provide the magnetic flux for operating the magnet, and to provide a single vehicle for inserting and removing the entire electromagnetic components in and from the relay.

To provide tight esngagement between the coil block 6 and the base frame -5, the block '6 is provided with spring engaging ramps Q0 along its underside which ride over and depress the springs '17 upn sliding the coil block 6 into the channel shaped base frame 5 from the front to the rear. Upper shoulders 21 are formed in the block 6 to slide beneath the inwardly turned ledges 1 2 and 13 of the frame 5 with a tight fit, in response to the resiliency of the springs 17. The upper shoulders 21 also include tapered risers 22 that can be moved beneath the ledges 13, upon application of sufiicient pressure during assembly of the coil block 6 in the base frame 5, and these risers 22 have sharp vertical for-ward'edge-s 23 which are caught behind the ledegs 13 when the block 6 is fully inserted, as shown in 1G. 1. This latch and catch arrangement securely holds the block *6 in place, and further movement in a rearward direction is precluded by front corners 24 of the coil block 6 engaging the notches 16 in ledges 12.

It will be observed that the coil block 6 can be inserted in the base frame 5 from only one direction, that is from the left to right as viewed in FIG. 1, and also as viewed in the associated FIGURES 5 and 6. Correct assembly of these two components is therefore assured, and since these as well as other components to be described can only be assembled in one orientation inexperienced personnel may handle the device either in manufacture or repair without special instruction.

The coil block 6 is formed with two vertical openings 25 of rectangular shape, as viewed from above, to receive the magnetic yoke 7 and armature 8. Operating coils embedded within the block 6 encircle these openings 25 to provide the necessary magnetic flux. A portion of one of these coils is shown in section in FIG. 4, and is designated by the reference numeral 26. The yoke 7 (see FIG. 7) is U-shaped and its legs are inserted from the bottom into the openings 25, so that it is held between the sheet metal plate 18 and a shock absorbant pad 27 afiixed to the undersurface of the coil block 6, as particularly shown in FIG. 4. The yoke may be held loosely between the plate 18 and pad 27 to minimize contact vibration upon relay operation. To ensure correct orientation of the yoke 7 within the coil block 6 a nib 28, as seen in FIG. 7, is formed in a side plate of the yoke 7 which fits into a mating notch in the block 6, as seen in FIG. 4.

The armature 8 (FIG. 8) is also U-shaped and it is received in a pocket 29 in the coilblock 6 which is immediately above the coil openings 25. The legs of the armature 8 then fit downwardly into the coil openings in facing relation to the upstanding legs of the yoke 7. The armature 8 then moves downward into engagement with the yoke legs upon energization of the coils 26. The pocket 29 has a floor 30 extending between the coil openings 25 with a spring seat formed therein, see particularly FIG. 6, and a pair of concentric springs 31 are seated upon the floor 30. These springs work against the underside of the armature 8 to move it into an upper position, away from the yoke 7, when the coils 26 are deenergized. It will be noted that one spring is a right hand spring, and the other is a left hand spring, so that torque due to spring movements which are applied to the armature 8 are suficiently neutralized.

The pocket 29 is composed of vertical walls adapted to engage the armature 8 for guiding its vertical movements, and the armature 8 is provided with a pair of side wings 32 that fit within guide channels 33 cut in the walls of the pocket 29. These channels 33 may also function to guide vertical armature movement. tain the armature 8 within the pocket 29 of the coil block 6, and hence to retain the springs 31 under compression, a small ledge 34 is formed in the front face of the armature 8 over which pivo'table pawl 35, secured to the block 6, is extended. The pawl 35 may be swung aside to permit insertion and removal of the armature 8 during assembly and disassembly, and to insure proper orientation of the armature 8 with the coil block 6 small tabs 36 .are formed in the armature side plates, as seen in FIG. 8, which mate with appropriate oblique, vertical faces formed as a part of the pocket 29. To complete the coil block 6 a pair of appropriate coil terminals 37 are provided at the forward end.

The lower contact housing The lower contact housing 2, shown in perspective in FIG. 17 as well as various elevational and sectional views in FIGS. 1, 9 and 11-.14 comprises a series of spaced, vertical, fore and aft ribs that form cavities therebetween. These ribs comprise a pair of outer ribs 38 that constitute side walls for the housing, a central rib 39 of slightly thicker cross section than the others, and intermediary ribs 40. Tying the ribs together is a substantially horizontal deck 41 and a rear Wall 42 which extends downwardly from the deck 41 and enclosesa part of the coil block 6, when the housing 2 is mounted in place upon the base frame 5. To mount the housing 2 upon the base frame 5 the outer ribs 38 are extended below the deck 41 to seat on the ledges 12-14, and they are notched at 43 to dove tail with the upstanding ears 11. The bottom surfaces of the ribs 38 are also slightly raised-at the forward ends 44 to seat upon the slightly raised ledges 14, and by reason of this mating construction the lower contact housing 2 can be mounted upon the side walls 10 of the magnet 1 in but one position.

The central rib 39 is sub-divided into fore and aft sections, and between these sections there is a manually operable, vertically movable plunger 45. The plunger To re- 4 41, and the spring 46 thus holds the plunger in a substantially raised position when no other forces are acting thereupon.

' The intermediary ribs 40 are also sub-divided into fore and aft portions, and they function to partition the housing 2 into a number of parallel adjacent cavities 47 that each receive an individual contact assembly 48, of a general configuration as best seen in the perspective view of FIG. 20. To receive the individual contact assemblies 48, the upper face of the deck 41 is shaped with a mating contour, as seen in FIGS. 12 and 13, and at each end of each cavity 47 is a threaded terminal screw socket 49 seated in the deck 41. Each contact assembly 48 includes a terminal screw 50 at each end, which in turn is received in an associated socket 49, and by tightening down the screws 50 the contact assemblies 48 are held in place. The terminal screws 50 also function to clampingly engage lead wires of an electrical circuit, as shown at the left hand side in FIG.- 12 for incorporating the contacts in such circuit. The construction and operation of the individual contact assemblies 48 will be described in greater detail hereinafter.

The upper contact housing The upper contact housing 3, shown in perspective in FIG. 18, is similar in many respects to the lower contact housing 2, with the major-exception that it is foreshortened in the fore and aft direction, so that the terminal screws 50 associated with the lower contact housing 2 are readily exposed for making connections into a circuit. Also, the under portions of the upper housing 3 are specifically shaped to properly seat upon the lower housing 2, and to house actuating springs for the contacts of the lower housing 2, as will be described. v

The upper housing 3 has a pair of outer ribs 51 which seat on the top edges of the outer ribs 38 of the housing 2, a central ri-b 52 that seats on the rib 39, and a pair of intermediary ribs 53 which are in alignment with the ribs 40. Tying the ribs together is a substantially horizontal deck 54, and the underside of the deck 54 includes a number of depending feet 55, as seen in FIGS. 9, l2 and 13,

with depending toes 56 at each end that fit over the contact assemblies 48 carried by the lower contact housing 2. Each foot fits snugly within a cavity 47 of the lower housing 2, to have a firm union between the housings 2 and 3, and each foot 55 includes a central opening that forms a spring containing well 57. In each well 57 there is a compression spring 58 which has its upper end seated against ears 59 extending into the associated well 57, and which has its lower end received and seated in a button 60 having a configuration as shown in FIG. 15. Each button 60 has a pair of upper flanges 61 which hook into the associated spring well 57, to thereby limit downward travel, and the associated spring 58 urges the button 60 into its lower position. movable with a vertical translation, and the purpose of the downwardly biased buttons 60 is to engage the contact assemblies 48 immediately therebeneath as actuators therefor. This operation will be discussed in greater detail hereinafter.

The underside of the upper contact housing 3 is further characterized by a downward extension of the central rib 52, as seen in FIG. 9, which fits within and mates with the central rib 39 of the lower contact housing 2. To

Hence, the buttons 60 are' screws pass through the housing 3 into the central rib 39 of the lower housing 2.

Cavities 63 formed between the ribs 5153 of the upper housing 3 are similar to the cavities 47 of the lower housing 2, except that they are foreshortened, and received in.

these cavities '63 is a plurality of individual contact assemblies 64, one of which is shown in FIG. 21. These assemblies seat upon threaded terminal screw sockets 65 at the forward and after ends of the cavities 63, and appropriate terminal screws 66 are employed, which are quite similar to the terminal screws 50. When the complete relay is viewed from above, as seen in FIG. 10, the banks of terminal screws 50 and 66 are exposed in parallel [banks for making ready connection with wiring brought to the relay.

3 The upper contact housing 3 also includes a manual plunger 67 that is received by the central rib 52, in similar manner as the plunger 45 is assembled in the lower housing 2. The plunger 67 is portrayed in perspective in FIG. 19, together with an associated spring 68 which functions like the spring 46, and its configuration as shown in FIG. 19 is quite similar to that of the plunger 45. The dif ferences in appearance are in their "outlines, which are clearly shown in FIG. 14. In FIG. 14 it is seen that the plunger 67 rests on the top of the lower plunger 45, and that the upper surface of the plunger 67 is exposed at the top of the relay. By depressing the top of the plunger 67 it is moved against the lower plunger 45, which in turn moves downwardly against the magnetic armature 8.

The armature 8, then, is depressed against the concentric springs 31 in a motion simulating an electrical operation of the relay. The springs 58 then move the contact actuating buttons, of FIG. 15, downwardly to operate the contact assemblies 48, 64 (which have an operation to be described), and hence a manual check of the contact operation of the relay can be had.

The cover The cover 4, shown in perspective in FIG. 16, fits over the upper contact housing 3, to cap this housing in a manner similar to the capping of the lower housing v2 by the upper housing 3. For this purpose, the cover 4 has a flat top 69 from which a set of four feet 70 depend that are similar to the feet 55. 'Each foot 70 is aligned with a cavity 63 f the upper contact housing 3, see FIG. 9, for snug receipt therein, and toes 71 on the feet 7 0 fit around the contact assemblies 64, as seen in FIGS. 12 and 13.

A spring well 72 is formed in each foot 7 0 that houses a spring 58 and -a button 60. Each spring -8 has its upper end abutting a pair of ears 73 at the top of the associated well 72, see FIG. 11, and the bottom end of each spring 58 works within its associated button 60, to urge the but-' ton 60 against the contact assembly 64 immediately below. The flanges 61 of the buttons 60 will catch against fingers 74, see 'FIGS. 12 and 1B, in the cover 4 to retain the assembly of the buttons 60 within the cover feet 70. To facilitate assembly of the buttons 60 into the spring wells 72, and also into the spring wells 57 of the upper contact housing, the buttons-60 are preferably molded of a material having some flexibility, such that the flanges 61 can be deflected inwardly as the buttons are inserted from the bottoms of the spring wells 57 and 72.

The cover 4 is formed with a central opening 75, through whichthe upper manually engageable plunger 67 protrudes, and a thin nameplate 76 is recessed in the top 69. A forward buttress 77 extends from the front edge of the cover 4 which has a beveled leading edge 78.

A rear buttress 79 extends from the after edge of the edge of the cover 4, and the buttresses 77, 79 are received in the central rib ,5-2 of the housing 3 when the cover 4 is assembled in place. Appropriate mounting screws hold the cover in position, and the 'beveled edge 78 mates with a mating, [beveled slot 80 in the rib 52, to ensure proper orientation of the cover *4 in a single direction of alignment with the housing 3.

7 from an eight pole relay to a four pole relay.

The contact assemblies The individual contact assemblies 48, 64 are quite similar to one another. Referring first to an assembly 4-8, as shown in FIG/2'0, it comprises a molded insulating body 81 with a hollow interior, as shown in FIGS. 1-1, 12 and 13. A conductive terminal member 82 at each end receives a terminal screw '58 that mounts the assembly 48. The conductive terminal members 82 of an assembly 48 extend inwardly to terminate in stationary contacts 83, that are spaced from one another as shown in FIGS. 12 and 13.

FIG. 12 shows an assembly 48 with the stationary contacts 83 at the top of body 81, and FIG. 13 shows an assembly 48 which is inverted to have the stationary contacts 83 at the bottom of the body 81. Thev position .of FIG. 12 is for a normally closed contact orientation, and the position of FIG. 13 is for a normally open contact orientation. FIG. 20 is similar to FIG. 13, in that the stationary contacts are in the lower position, and FIGS. 12 and 13 further show that when a contact assembly 48 is inverted there is no vertical displacement of the body 81.

A contact actuator 84 is received in each contact assembly 48 which has a box-shaped central portion 85 from which protrude vertical stems 86 and 87. A movable contact spanner 88 is inserted in each box-like central portion 85 for bridging the associated stationary contacts 83, and a contact spring 89 is inserted behind each spanner 88. Thus, when a contact assembly 48 is inserted in the normally closed position of FIG. 12, the spring 89 holds the contacts closed when the relay parts are in normal position, and when a contact assembly is inserted in normally open position, as in FIG. 13, the spring 89 will provide a closing force when the relay parts are moved into energized positions.

Whether a contact assembly 48 is inserted in normally I open or normally closed position the lower stem, 86 or 87,

will extend through the deck 41 to rest upon the magnetic armature 8 or one of its side wings 32. Thus, the actuators 84 are normally held in raised positions, and the armature 8 is shown in phantom in FIGS. 9 and 11 to illustrate this positioning.

The buttons 60 in the spring wells'57 of the upper contact housing 3 rest upon the box shaped central portions of the contact actuators 84, and the upper stems 86 or 87 enter the buttons 60 in an alignment concentric with the springs 58. Hence, the upper stems 86 or 87 are in positions for engagement with the stems of contact assemblies 64 in the upper housing 3. Also, as shown in FIGS. 12 and 13, the buttons 68 are normally raised, with a corresponding compression of the springs 58, so that when the armature 8 is depressed upon energization of the coil 26 the springs 58 will move the contact actuators 84 downwardly to effect a contact operaton.

Each of the upper contact assemblies 64 mounted in upper housing 3, one of which is shown in FIG. 21, has a molded body 90 with a terminal member 91 at each end. Each terminal member 91 includes a stationary contact 93, and associated with each terminal member 91 is a metal tab 92 on the reverse side of the body 90. Each tab 92 has a tubular part extending through the body 98 and riveted to the member 91 to have a unitary terminal. Electrical engagement is then made with a control circuit wire for either position of inversion of an assembly 64. The molded bodies 90 also receive contact actuators 94 with box-like center portions 95 and protruding stems 96,

actuator 94 and contact springs 98 are also included in the assembly.

The contacts of the assemblies 64 are disposed in normally open or normally closed positions by selecting the appropriate positions of inversion, similarly as in the instance of the lower contact assemblies 48. In FIG. 12, for example, a contact assembly 64 is shown with its terminal members 91 on the upper side, and this is the normally closed position. In FIG. 13, a contact assembly- The operation of the complete relay may now be summarized. In normal, unenergized condition of the electro magnet 1, the armature 8 is held raised by the two compression springs 31. The armature, in turn, holds the sev eral, individual contact actuators 84, 94 in raised position. This positioning holds the several contact actuating springs 58, 73 compressed. Upon energization of the coil 26 the armature is forced magnetically downward into engagement with the yoke 7, forces of the impact being absorbed in part by the plate 18, the cushion 19 and the pad 27. The several springs 58, 73 now move the contact actuators 84, 94 and their contact spanners 88 downward to contact actuated positions.

Upon deenergization of the electromagnet assembly 1 the springs 31 return the armature 8 upward and the contact spanners 88 move correspondingly to their normal positions. Thus, the contacts are operated in response to spring pressures for both opening and closing and this operation is for both normally closed and normally open arrangements.

The invention provides a relay having the several advantages enumerated in the introductory remarks. One of the principal advantages is the ability to remove the magnet components without disturbance of the contact assemblies. This removal is readily effected by placing a tool, such as a screwdriver, in the coil block 6 at the vicinity of the tab 35, then pushing down and using the screwdriver as a lever with the fulcrum at a point on the contact housings to move the tool point forward. Thev coil block 6, yoke 7 and armature 8 will then be translated forwardly as a unit for discharge from the channel shaped base frame 5. In removing and reinserting parts of the magnet assembly the contact assemblies are undisturbed. In the absence of the armature 8 the contact actuators 84, 94 are depressed in response to the several springs 58, 73, and hence the lower actuator stems 86 or 87 protrude beneath the deck 41 of the lower contact housing 2. So that these stems do not interfere with reinsertion of the armature 8, the leading edge of the armature 8 is beveled, as at 8' in FIG. 8. As a result, the armature 8 slides clear of any blocking interference with the contact assemblies upon removal and reinsertion. If desired, the yoke'fl can be held within the coil block 6 by a tab 99, shown in FIG. 2, screwed to the underside of a small boss 100 molded as an integral part of the underside of the coil block 6.

The invention also provides contact assemblies in a relay that can be quickly replaced or changed from nor.

mally open to normally closed position. Versatility is achieved, and a highly desirable relay structure is made available.

We claim:

1. In an electromagnetic relay the combination comprising: a channel shaped base with a central floor and opposite side walls, said side walls having inwardly extending overhanging retaining ledges; a coil block posi- 10 tioned within said channel shaped base with a coil opening substantially normal to said central floor, said coil block being translatable through the channel of said base for removal from and insertion into the base; resilient means holding said coil block between said retaining ledges and said floor; catch means restraining the coil block from said translation when the coil block is inserted in the channel of said base, and disengageable for permitting said translation of said coil block; a magnetic yoke interposed between said central floor and said coil block'with a portion extending into said coil open-ing from the bottom thereof, said yoke being translata ble with said coil block upon removal and insertion thereof; a magnetic armature depending into's aid coil opening from the top thereof and held in bearing engagement with walls of said coil block for guided movement toward and away from said yoke, said armature being translatable with said coil block upon removal and inserti-on thereof; spring means interposed between said armature and said coil block urging the armature from the yoke; a catch limiting the movement of said armature :from said yoke; a contact housing mounted upon said retaining ledges of said base that is clear of the path of travel of said coil block, armature and yoke upon said translation of the coil block; said contact housing comprising a plurality of parallel, spaced ribs forming pockets therebe'tween and a deck extending between ribs defining the bottoms of the pockets, and a pair of said ribs depending from the deck and seated upon said ledges as a mounting support for the housing; a plurality of removable and invertable contact assemblies disposed within said pockets each having a contact actuator that protrudes from beneath said deck for engagement by said armature and that extends upwardly for engagement from above; a cover fitting over said housing witha plurality of displaceable spring seats mounted therein and aligned with said contact actuators of said contact assemblies for engagement therewith; bias springs seated in said cover that bear against said spring seats and urge the same against said contact actuators; and a depressable manual operator mounted by said cont-act housing engageable with said armature for movement thereof and resultant switch contact operation in response to said bias springs.

*2. In an electromagnetic relay the combination comprising: a base with a floor, side walls rising from opposite sides of the floor, and retaining ledges at the tops of said sides; a coil block carried by said base in a position above the floor and between the side walls that is translatable longitudinally of the side walls for removal from and insertion into said base; means for holding said coil block between said retaining ledges and said floor; a magnetic yoke associated with said coil block; a movable magnetic aramature associated with said coil block; a contact housing mounted upon said base that is clear of the path of travel of said coil block upon translation into and from said base; a plurality of contacts carried by said housing; and contact actuators for said contacts engageable with said armature for cont-act actuation in response to armature movement which are free from obstruction of armature movement occasioned by said translation of said coil block.

3. An electromagnetic relay in accordance with claim 2 in which said coil block extends from between said side walls above said base, and said contact housing has side walls and one end wall that fit :around said block to house the upper portion thereof and is open at the other end to allow said translation of said block.

4. In an electromagnet the combination comprising: a channel shaped base with a central floor and opposite side walls, said side walls having inwardly extending overhanging retaining ledges; a coil block positioned within said channel shaped base with a coil opening substantially normal to said central floor, said coil block .being' translatable through the channel of said base for removal from and insertion into the base; resilient means holding said coil block between said retaining ledges and said fioor; catch means holding the block from translation and disengageable for eifecting translation of the coil block; a magnetic yoke interposed between said floor and coil block with a portion extending into said coil openingmfrom the bottom and translatable with said coil block; a movable magnetic armature depending into said coil opening from the top and in bearing engagement with walls of said opening; spring means interposed between said armature and coil block urging the armature from the yoke; and a catch limiting the upward movement of said armature from said yoke.

5. In an electromagnet the combination comprising: a channel shaped base with a central floor, opposite side walls, and retaining ledges; a coil block within the channel shaped base with an opening substantially normal to said central floor, said coil block being translatable into and from said channel in a direction longitudinally of said side walls; resilient means holding said coil block be tween said retaining ledges and said floor; catch means holding the coil block from translation when in said base and disengageable for effecting translation of the coil block; a magnetic yoke associated with said coil block that extends into said coil block opening and is translatable with said coil block; a movable magnetic armature depending into said coil block opening from the top in bearing engagement with walls of said opening for guided vertical movement toward and away from 'said yoke, and which is translatable with said coil block;

and spring means interposed between said armature and coil block urging the armature from the yoke.

6. In an electromagnet the combination comprising: an open ended base frame with a floor and opposite side walls rising from the floor; a coil block slidable into and from a position between said side Walls by movement through an end of saidbase frame, which coil block has releasable catch means engageable with said frame to restrain the same from such slidable motion, said coil block having a pair of coil openings and armature engaging bearing walls continuing from the coil openings; a U-shaped magnetic yoke with the legs thereof inserted into said coil block coil openings from the underside of said block; and a U-shaped magnetic armature with the legs thereof depending into said coil block coil openings, which armature is guided by said bearing walls of the coil block in movement toward and away from said yoke; sa-id coil block, yoke and armature being movable as a group upon sliding motion of said coil block 'into and from said base frame.

7. The apparatus of claim 6 in which the releasable catch means comprises an inclined ramp and an ear under which said ramp slides, one being on said coil block and the other on said base frame.

-8. The apparatus of claim 7 in which said base frame has a stop limiting sliding movement of said coil block to one side only and to a predetermined amount.

9. The apparatus of claim 6 in which said yoke has a protrusion and said coil block has a mating recess thereby limiting insertion of the yoke into the coil openings to one position of orientation.

10. The apparatus of claim 6 in which said armature has a protrusion and said coil block has a mating recess thereby limiting insertion of the armature into the coil openings to one position of orientation.

11. The apparatus of claim 6 in which the floor and side walls of said base frame comprise a channel, said side walls have retaining ledges facing toward the floor, and said coil block has retention surfaces facing said retaining ledges; there further being resilient springs on said floor which engage the underside of said coil block and tightly hold said retention surfaces and retaining ledges against one another.

12. The apparatus of claim 6 having a pair of armature springs urging said armature away from the yoke, which springs are coils concentric with one another with one being a right hand spring and the other a left hand spring.

13. In an electromagnet the combination comprising: a molded coil block having a central pocket with vertical guide walls and a floor, said floor having a pair of coil openings, continuing downward from said pocket through the bottom of the block, and said coil block further having upper and lower mounting surfaces; a magnetic armature received within said pocket of said coil block with vertical surfaces in bearing relation to the guide walls of said block, and with downwardly turned legs extending into said pair of coil openings; a magnet c yoke on the underside of said coil block with upwardly turned legs extending into said pair of coil openings; and a frame mounting said coil block in tight engagement with said upper and lower mounting surfaces.

14. An electromagnet as in claim 13 having a floor for said frame, a resilient cushion associated with said floor, and said yoke being held between said cushion and said coil body.

15. An electromagnet as in claim 13 with a contact housing on said frame rising above said armature, and having contact actuators bearing upon the armature for movement in response thereto.

16. A relay assembly comprising: a'contact housing having a plurality of parallel, spaced ribs forming pockets therebetween, and a deck extending between ribs defining the bottoms of the pockets which has an opening in each pocket; a pair of said ribs depending from the deck serving as a mounting support for the housing; a plurality of separate removable contact assemblies each disposed within one of said pockets and including stationary and movable contacts, terminals for connection into a circuit, and a contact actuator which is accessible from beneath said deck through a deck opening and which is also accessible from above said housing; a separate, removable cover fitting over said housing having a plurality of displaceable spring seats aligned with and engageable with said contact actuators of said contact assemblies; and bias springs seated in said cover that bear against said spring seats and urge the same against said actuators.

17. A relay assembly as in claim 16 with a magnet attached to and supporting said pair of ribs of said housing, which magnet has an armature beneath said deck and in operative relation with the portionsot said contact actuators accessible from beneath said deck.

18. A relay assembly comprising: a first contact housing having a deck and a plurality of parallel, spaced ribs rising from the deck; a plurality of invertable, removable contact assemblies each disposed between a pair of said ribs and comprising movable and stationary contacts, terminals at each end for connection into a circuit, and movable contact actuators with lower ends protruding through said deck and upper ends exposed at the upper side of said housing; a second contact housing seated upon said firsthou sing having a deck and a plurality of parallel, spaced ribs rising from the deck, a plurality of invertable, removable contact assemblies each disposed between a pair of said ribs of the second housing and comprising movable and stationary contacts, terminals at each end for connection into a circuit and movable contact actuators with lower ends protruding through the associated deck that bear upon the contact actuators of the contact assemblies of the first housing and with upper ends at the upper side of the housing; a plurality of discontact assemblies of the first housing; bias springs in 13 and engageable therewith; and bias springs seated in said cover that bear against said spring seats and urge the same against said contact actuators of the second housing.

19. A relay assembly of claim 18 in which said first contact housing is mounted upon a magnet, said magnet having an armature engageable with the con-tact actuators of the contact assemblies of said first housing for operating the same.

20. A relay assembly of claim 19 in which a manual operating plunger is mounted in each housing, one above the other and engageable with one another, the plunger of said first housing engaging said armature, and depression of the plunger in the second housing causing depression of the armature.

References Cited by the Examiner UNITED STATES PATENTS 2,811,617 110/1957 Townsend 200166 3,099,730 7/1963 Tateishi 200104 3,109,905 1-1/1963 Marquis 200166 X 3,178,534 4/1965 Bundy et al. ZOO-=87 BERNARD A. GILHEANY, Primary Examiner. R. N. ENVALL, JR., Assistant Examiner. 

2. IN AN ELECTROMAGNETIC RELAY THE COMBINATION COMPRISING: A BASE WITH A FLOOR, SIDE WALLS RISING FROM OPPOSITE SIDES OF THE FLOOR, AND RETAINING LEDGES AT THE TOPS OF SAID SIDES; A COIL BLOCK CARRIED BY SAID BASE IN A POSITION ABOVE THE FLOOR AND BETWEEN THE SIDE WALLS THAT IS TRANSLATABLE LONGITUDINALLY OF THE SIDE WALLS FOR REMOVAL FROM THE INSERTION INTO SAID BASE; MEANS FOR HOLDING SAID COIL BLOCK BETWEEN SAID RETAINING LEDGES AND SAID FLOOR; A MAGNETIC YOKE ASSOCIATED WITH SAID COIL BLOCK; A MOVABLE MAGNETIC ARMATURE ASSOCIATED WITH SAID COIL BLOCK; A CONTACT HOUSING MOUNTED UPON SAID BASE THAT IS CLEAR OF THE PATH OF TRAVEL OF SAID COIL BLOCK UPON TRANSLATION INTO AND FROM SAID BASE; A PLURALITY OF CONTACTS CARRIED BY SAID HOUSING; AND CONTACT ACTUATORS FOR SAID CONTACTS ENGAGEABLE WITH SAID ARMATURE FOR CONTACT ACTUATION IN RESPONSE TO ARMATURE MOVEMENT WHICH ARE FREE FROM OBSTRUCTION OF ARMATURE MOVEMENT OCCASIONED BY SAID TRANSLATION OF SAID COIL BLOCK. 